Non-paternal events (abbreviated NPE and also known as
not-the-parent-expected) may be much more common than is often
recognized and may, in fact, be the reason so many Taylors have difficulty in
their genealogical research. And, why they've turned to genetic genealogy
We are careful in discussing this subject; learning that one's direct
paternal lineage isn't what one believed can be an unpleasant surprise.
However, we believe that truth is usually better than falsity.
NPE are also sometimes termed "not the parent expected" or "incorrectly ascribed paternity".
For our purposes, it means a discontinuity in paternally-inherited surname — any
event and/or series of events which lead to a child not bearing the
surname his or her biological father was born with.
The diagram depicts a NPE producing a brick wall at the earliest known
paternal ancestor. The actual paternal
lineage is shown by the green line.
What's not a NPE?
We do not consider spelling variants (e.g., Taylor vs. Taylour) to be NPE
because they were
so common in the past. Prior to about 1840, standardized spelling was an unknown concept;
names were written according to the way the writer heard them and his (often idiosyncratic) notions of how to write that sound.
No, not rare at all. Estimates vary from a low of 1% to as high as
10% of all births in a generation being NPE. Rates vary considerably depending on cultural norms, socio-economic
conditions and other factors.
NPE are cumulative; the changed surname tends to continue down the lineage.
Let's say that you want to look eight generations into the
past, to find the parents of your 5th great-grandfather.
- At a per-generation NPE rate of 1% -- 8% of all paternal
lineages are likely to have an NPE in the
8-generation paternal tree.
- At a per-generation NPE rate of 3% -- 22% of all paternal lineages
are likely to have an NPE in the
Only 78% do not.
- At the higher rate of 10% -- 57% of lineages have an NPE. Only 43%
Since Y-DNA looks back very far indeed, it would be rare that an NPE or so
doesn't turn up.
A recent study of Taylor project members looked at the NPE prevalence question from
the standpoint of Y-haplotype matches with the project surname vs. other
names. It found that the probable rates for
the two types of NPE were
- iNPE -- 27%
within genealogical timeframe. Assuming 24 generations, this calculates
to a rate of ~1% per generation.
- eNPE -- 11%
within genealogical timeframe. Assuming 24 generations, this is a rate
of ~0.5% per generation. (We suspect this 11% is an under-estimate.)
In a recent instance, a project member had successive NPE within two
generations, one right after another.
NPE may be classified into one of two types:
- iNPE -- for ingression. A new Y-DNA haplotype enters the surname.
A biological father had another surname but his child's surname is
- eNPE -- for egression. The haplotype formerly associated with the
surname leaves it. A biological father's h surname was Taylor but his
child's surname is another.
Such classification is only relevant to a particular surname. Every NPE is
an iNPE for one name and a eNPE for another.
The different causes of NPE include, but are not limited to:
- Adoption, formal or informal, in which the child takes the name of
the adoptive father;
- Name change by alias, corruption or other means;
- Example: A man born in 18th century Quebec with the name "Jean Baptiste Perrin" moved to
English-speaking New Hampshire and became known as "John Bettis". His
modern descendants carry the Bettis surname; it took DNA testing to uncover
his Perrin ancestry.
- In some cultures, a man marrying into a farm-owning family would
take that family's surname, the "farm name".
- In some cultures, a man might take his wife's surname.
- We do not usually include spelling variations as NPE. They were
so common before the mid-19th century, that we consider the
- The culture may use patronymic practices -- the child's surname
the father's given name with a prefix or suffix;
- Examples: O'Neal, FitzGerald, MacDonald, McKinney, Anderson, Andersen,
- Scandinavian countries used patronymic systems and did not fix surnames by family until the
- Alias, the father changes his surname or it is changed for him;
- The McGregor surname was banned in 18th-century Great Britain.
Those with it were compelled to take another name.
- The father may want to disguise a previous identity.
- The father's true surname may not be intelligible to the
community in which he lives. For example, Jean Baptiste Perrin's
French-Canadian name was changed by his New York community to John
- Debbie Kennett, in "The Surnames Handbook", uses alias in
a different sense and cites an example of a family
which was alternately known by Rowberry and Gomberry and variations of those names.
The reasons for the alternate names isn't given.
- Illegitimacy in which the child takes the mother's surname;
- Adultery in which the child takes the mother's husband's surname
rather than the child's biological father's;
- Sperm donation with results similar to adoption or illegitimacy;
- The father may not have had a surname; He may have come from a
culture which didn't use them, but the child is born into a culture
- Or, a host of other events.
In general, bear in mind that surnames are a modern invention and more
flexible and fluid than we tend to think.
How to tell if there's an NPE in my tree?
There are clues.
- If your tree stops at a particular generation and -- despite diligent
research -- parentage behind it is
hidden behind a brick
wall, the explanation could be NPE. It may be that ancestor's father had a
different surname than the one you've been researching.
- If you have no Y-DNA matches within your surname, but many
with another, particular surname, your biological paternal ancestor may have
born that surname rather than the one you've thought.
- To see this, you must not have restricted your search for
matches to your own surname or to members of a particular surname
- If your matches have a wide variety of surnames and no discernible
pattern, the likelihood is that you have a common type of Y-DNA.
It's especially applicable for those who are close to the Western
Atlantic Modal Haplotype or the Niall of the Nine Hostages haplotype.
- If a few people with other surnames match you but you also have matches
within your surname, it's possible that the few (and not you) have NPE in their trees.
- If the surnames appear predominantly Scottish or Irish, this could
reflect ancestral clan membership.
- If the surnames show no particular pattern and you have many matches, it
may be due to convergence toward your haplotype.
If your tree stops at a brick wall and you have matches outside your
surname, NPE may be the reason for both. It is time to seriously consider
How to deal with NPE; reaching beyond the brick
First, remember that your ancestors were just as human as any others
who've walked the earth. Stuff happens and there's no reason to be
embarrassed. It's not your fault and doesn't reflect on you.
Be sure not to restrict your search for DNA matches only to your
own surname. The matches you need may be lurking just beyond your vision.
Next, recognize that NPE are often undocumented. Pulling out the facts
may be difficult and may rely more on indirect genealogical evidence than
Only diligent research, focused on concrete facts, can unravel the mystery.
Narrow down the date, place and circumstances of that earliest known ancestor's
birth to the maximum extent possible. Put out of your mind what your earliest
known ancestor did as an
adult -- unless it bears on his birth. Who he subsequently married and what children he had is
not especially relevant to his parentage.
Search records of bastardy bonds, guardianships and apprenticeships -- if
only to eliminate them as sources. You just might get lucky here. Look at
deeds, wills and probates. Again, you might get lucky with a mention of your
Remember that (until very recently) for a birth to occur, mother and father
must have had physical contact with each other. Usually, the contact was more
than brief; they knew each
other socially before conception and that implies proximity of residences. They
met at church or community events and were attracted to each other.
- NPE seem especially more frequent during wars and other social or
- The "traveling salesman and farmer's daughter" scenario is rare;
most couples had a longer-term relationship.
- Prior to the 20th century most women were at home with family, making the "one-night-stand" scenario unlikely.
- This may have changed in the 1920s. Women began experiencing greater
social and sexual freedom.
The state, even the county, isn't an adequately precise location for
birthplace or mother's home; you'll need to know the
specific neighborhood, usually within walking distance. Were there nearby families with the other surname? Did they have
sons of the right ages? Were any known as "ladies men" or did any disappear out of the area?
You will need to do an "exhaustive search" of records in that place to be
certain you haven't overlooked relevant evidence. Pull all the information
together by forming a working hypothesis and listing the arguments for and
An entertaining and educational account of a 20th century adoptee's search for his
birth family and, by extension, his ancestry is Richard Hill's "Finding Family:
My Search for Roots and the Secrets in My DNA". (ISBN 13: 9781475190830)
Finally, be sure to read this
page on the ISOGG site.